Oracle 1z0-071 Exam With Confidence Using Practice Dumps

A look at the queries and how Oracle Database handles data type conversion:

A: This statement takes a substring of the JOIN_DATE column. Since JOIN_DATE is a DATE type and SUBSTR function expects a string, implicit conversion will occur from DATE to string based on the NLS_DATE_FORMAT setting. However, this will not require explicit conversion in the query itself.

B: This statement tries to add '20' to JOIN_DATE. Oracle Database does not support adding a string to a DATE implicitly. An explicit conversion of '20' to a number is required, or using the INTERVAL keyword to add days or years as appropriate.

C: This statement concatenates the date with an empty string and the salary. The database will implicitly convert the JOIN_DATE from a DATE to a string using the NLS_DATE_FORMAT setting and then perform the concatenation.

D: This query attempts to compare a DATE column with a string literal '*10-02-2018'. An explicit conversion using TO_DATE is needed to convert the string to a DATE data type with the appropriate date format mask. In this case, because the string does not follow the NLS_DATE_FORMAT 'DD-MON-YY', it will not be implicitly converted correctly.

E: This statement adds '120.50' to SALARY. Oracle Database will implicitly convert the string '120.50' to a number before performing the arithmetic addition, as SALARY is a NUMBER data type.

C. True, the names of the columns in each SELECT statement of an INTERSECT query do not need to match, as long as the data types and order of the columns correspond.D. True, the INTERSECT operator returns only the rows that are common to both SELECT statements, effectively acting as a set intersection of the results from both queries.

References:

Oracle documentation on INTERSECT operator: Oracle Database SQL Language Reference

Detailed behavior of INTERSECT: Oracle Compound Queries

Key components of an Entity-Relationship Model (ERM) include:

B. an attribute: Attributes are properties or characteristics of an entity, such as a person's name, date of birth, etc., and are essential in describing the data aspects of an entity in an ER model.

E. a relationship: Relationships describe how entities interact with each other within the database structure, such as a customer placing an order.

F. an entity: Entities are the key components of an ER model, representing objects or things within the domain that have a distinct existence, like 'Customer' or 'Order'.

Incorrect options:

A: A table is a database structure used to implement an entity in relational databases, not a component of the ER model itself.

C: While unique identifiers are crucial in database implementation (typically as primary keys), they are a specific attribute type, not a general component of ER models.

D: An activity is not a component of an ER model; activities relate more to process models or behavioral models in systems design.